ZDI-11-136: IBM Tivoli Directory Server ibmslapd.exe SASL Bind Request Remote Code Execution Vulnerability

[ZDI Disclosures <zdi-disclosures@xxxxxxxxxxxxxxxx>]

ZDI-11-136 (formerly ZDI-CAN-1022): IBM Tivoli Directory Server ibmslapd.exe 
SASL Bind Request Remote Code Execution Vulnerability

http://www.zerodayinitiative.com/advisories/ZDI-11-136

April 18, 2011

-- CVE ID:
CVE-2011-1206

-- CVSS:
10, (AV:N/AC:L/Au:N/C:C/I:C/A:C)

-- Affected Vendors:
IBM

-- Affected Products:
IBM Tivoli Directory Server

-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability by Digital Vaccine protection filter ID 11092. 
For further product information on the TippingPoint IPS, visit:

    http://www.tippingpoint.com

-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of IBM Tivoli Directory Server. Authentication
is not required to exploit this vulnerability.

The specific flaw exists in how ibmslapd.exe handles LDAP CRAM-MD5
packets. ibmslapd.exe listens by default on port TCP 389. When the
process receives an LDAP CRAM-MD5 packet, it uses libibmldap.dll to
handle the allocation of a buffer for the packet data. A specially
crafted packet can cause the ber_get_int function to allocate a buffer
that is too small to fit the packet data, causing a subsequent
stack-based buffer overflow. This can be leveraged by a remote attacker
to execute arbitrary code under the context of the SYSTEM user.

-- Vendor Response:
IBM has issued an update to correct this vulnerability. More
details can be found at:

https://www-304.ibm.com/support/docview.wss?uid=swg21496117

-- Disclosure Timeline:
2011-02-17 - Vulnerability reported to vendor
2011-04-18 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by:
    * Francis Provencher for Protek Research Lab's

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